Backward positioning of parts and sub-assemblies

bill_daniels

I am involved in positioning many parts and sub-assemblies in a master assembly.  Of course, they almost never import into the final position needed in the master assembly.

It occurs to me that it would be very nice if, once positioned correctly in the master assembly a part could then be easily re-positioned in its part studio so if imported again into the master assembly, it would appear in precisely the position needed. I know mate connectors can be used but if one could just click on a part in the master assembly and check a box that would cause the part to re-position itself in the part studio, it would make part changes easier.

lougallo

@bill_daniels I pulled this out of the improvement requests site to get more information about what you are after here.  When you import it is set at the origin but you can always move your cursor into the assembly to position it.  Any other input will help.

3dcad

I think @bill_daniels is after changing the default position permanently. So that if you position part in assembly once, you could save that position as part default position. Any re-inserts would then automatically position to new default place and that transform would also apply to corresponding part studio / sub-assembly.

bill_daniels

3D CAD put it much better than I did.  Actually, after thinking about it more, it might work better if there was an option where changing the position of a part in an assembly was reflected back to the part studio so it re-inserts in the final position next time.  Same with sub-assemblies.

Lou, automatically positioning a part at the origin is often not convenient as the origin is sometimes buried inside the assembly.  I know that I can just place the mouse cursor where I want the inserted part or sub-assembly to appear but this is often slow.  It would be much better if the part or sub-assembly just appeared in its final position.

It's true that many times that "re-inserting" is solved with in-context editing which eliminates jumping back to a part studio but it doesn't work with sub-assemblies and there are other times where working in a part studio is easier than in-context.

Tony_C_

This is kinda what I was talking about here.

https://forum.onshape.com/discussion/comment/26767/#Comment_26767

The ability to edit a sub-assembly in-incontext within the main assembly is what I think is needed.  Not sure if that's doable though.  

bill_daniels

Let me add another perspective to help explain what I'm after.

If a part is created in an assembly using in-context editing, it will be offset from the origin in its part studio so if it is re-inserted, it will appear in the assembly exactly where it was created.  i.e. no re-positioning will be necessary.  Very useful.

I'd like an easy one-click ability to re-position parts in their studios from within an assembly so they will then appear in the correct position when re-inserted. This would be used where a part was created in a studio before its location in an assembly was known. This would make it very easy to create different versions of assemblies. It would also make it very easy to modify a part in its studio while maintaining its relative position in the assembly.

3dcad

@bill_daniels
I can see few problems here:
- Multiple instances added to same assembly, how to position in part studio
- Part studio constraints, if part has mirrored features where default planes were used or dimensions to origin / planes = disaster
- Linked documents - can't reposition locked version

Though I would benefit from feature like this, I think it has too many strings attached. I would prefer 'replace part' feature for assembly so that you could exchange part to similar part with mates updating automatically. Replace part is common feature for mcads and Onshape is probably already working on that.

I would also like to see a way to automatically update assembly with any part studio changes (position, new parts, etc..) - if complete ps was added to assembly. 

bill_daniels

3dacd, I can see those problems.

However, I just updated a part with multiple instances in an assembly.  The part had originally been made with in-context editing so its position was correct in both the assembly and the part studio.  When I went back to the assembly, all instances of the part were updated and in their correct position.

As for mirroring, I do have problems with positioning.  If the mirrored parts were re-positioned in the part studio to the correct relative position for the next higher level assembly, I think that would work.

By 'locked' I'm assuming you mean fixed.  I just inserted a fully fixed sub-assembly into a higher level assembly and found none of the sub-assembly parts were fixed.  I had to group the sub-assembly to position it and then un-group it.  Had the subassembly been in the correct relative position, it would have just 'popped' into place.

3dcad

@bill_daniels
By locked I mean that if you link part studio from another document, you need to first create a version and then link to that version. Versions can't change, ever. That is mainly good thing because it makes links robust against unwanted changes but it can be also annoying for library type of documents.

So if you wan't to change something in linked doc through assembly in another doc - it would need to create new version for changes and update link.

I think your idea would work better if it would only save new default place for certain part studio parts in certain assembly and keep part studio as it is - but I suppose mates are there for that purpose..

malay_kumar

Good discussion. This is somewhat related to what @Tony_C_ was discussing in terms of updating subassembly position from top-level. What do you guys mean by "re-inserts" or "... imported again"? Generally one shouldn't need to re-insert or import again. I can see cases where part goes bad because of history changes significantly and need reinsertion. Is that what you guys are running into here? Even then if parts are grouped just after inserting in same relative position then it should work fine. If part was positioned using mates then after insert it will need to be mated again. Are you trying to avoid to mate again because it was mated before (and potentially just group it)?

3dcad

@malay_kumar
I can only speak for myself but I re-insert complete studios sometimes so that I can use group for whole ps and a single mate for position whole group.
I would rather fix my issues with 'live part studio insert' which would automatically apply any new parts and positioning from part studio.

Replace part would be handy for imports and also for standard parts while waiting for configurations (and applying them into current libraries).

malay_kumar

Thanks @3dcad. Yes that is a valid use case when inserting whole part studio or even a subset of part's grouped as positioned in part studio and later adding/removing parts in part studios. I don't think however we would want to update part studio part's position in this case based on assembly position though. We have thoughts about ways to support this workflow in future without needing to reinsert. One workaround currently may be to have a subassembly for partstudio's part placed at at origin and and a group in sub and use subassembly everywhere else in place of part studio. Then one will have to just update sub-assembly with new parts/removed parts and edit group. May not be an ideal solution from BOM etc point of view but a workaround.